Merge pull request #4117 from mysterywolf/time1

[bug][keil][libc]修复开启pthread功能后keil报错的问题

components/libc/compilers/armlibc/sys/unistd.h

@@ -68,4 +68,6 @@
 int     isatty      (int fd);
 char *  ttyname     (int desc);
 
+unsigned int sleep(unsigned int seconds);
+
 #endif /* _SYS_UNISTD_H */

components/libc/compilers/common/sys/time.h

@@ -36,6 +36,13 @@ struct timeval {
 };
 #endif /* _TIMEVAL_DEFINED */
 
+#ifndef _TIMESPEC
+#define _TIMESPEC
+struct timespec {
+    time_t  tv_sec;     /* seconds */
+    long    tv_nsec;    /* and nanoseconds */
+};
+#endif
 
 struct timezone {
   int tz_minuteswest;   /* minutes west of Greenwich */

components/libc/compilers/dlib/sys/unistd.h

@@ -40,4 +40,6 @@
 int     isatty      (int fd);
 char *  ttyname     (int desc);
 
+unsigned int sleep(unsigned int seconds);
+
 #endif /* _SYS_UNISTD_H */